The present invention relates to electric lawn mowers of the type which includes a cutter blade driven via an electric motor mounted in a machine body section and a handle extending rearward from the machine body section, and in which a switch operation mechanism for performing ON/OFF control of the motor is provided on the handle.
Electric lawn mowers are known, for example, from Japanese Patent Laid-open Publication Nos. HEI-6-38611 and HEI-9-36. The electric lawn mower disclosed in the HEI-6-38611 publication includes first and second housings mounted on left and right side portions, respectively, of a handle, and a handling lever pivotally connected to the first and second housings. A power switch and activation button are accommodated in the first housing so that the power switch can be turned on/off by a proximal end portion of the handle operating on the activation button.
The electric lawn mower disclosed in the HEI-9-36 publication includes a clutch lever pivotally connected to a grip portion of the handle, and a cutter-blade clutch switch provided on a proximal end portion of the handle. Here, the cutter-blade clutch switch is operatively connected to the clutch lever by means of a connecting spring in such a manner that it can be controlled remotely via the clutch lever.
However, in the first-mentioned prior art electric lawn mower, there has to be provided the activation button between the handling lever and the power switch to achieve matching between the pivoting range of the handling lever and the switching stroke of the power switch, and thus a complicated structure would be required for the switching operations. Further, in the second-mentioned prior art electric lawn mower, there has to be provided the connecting spring between the cutter-blade clutch switch and the clutch lever and the switching stroke of the clutch switch, and thus the switching operations tend to be inaccurate.
In view of the foregoing prior art problems, it is an object of the present invention to provide an improved electric lawn mower which includes a switch operation mechanism that, with a simple and direct switching structure, permits accurate switching operations for ON/OFF control of a cutter-driving electric motor.
In order to accomplish the above-mentioned object, the present invention provides an electric lawn mower of a type which generally comprises an electric motor mounted in a machine body section for driving a cutter blade, a handle extending rearward from the machine body section, and a switch operation mechanism provided on the handle for performing ON/OFF control of the electric motor. In the present invention, the switch operation mechanism includes a handling lever pivotally connected to a portion of the handle, a generally-fan-shaped actuating member pivotally connected at a pivot portion thereof to the handle in such a manner that the actuating member is pivotable in response to operation, by a human operator, of the handling lever, and a noncontact switch, preferably in the form of a noncontact reed switch, for turning on or off the electric motor in accordance with an ON/OFF state of the noncontact switch. The ON/OFF state of the noncontact switch is determined in accordance with pivoting movement, toward or away from the noncontact switch, of the actuating member responsive to the operation of the handling lever.
The noncontact switch, preferably in the form of a noncontact reed switch, is provided for turning on or off the electric motor in accordance with its ON/OFF state. To determine the ON/OFF state of the noncontact switch, the generally-fan-shaped actuating member is pivotally connected at its pivot portion to the handle in such a manner that the actuating member can pivot in response to operation, by the human operator, of the handling lever. Here, the noncontact switch is set to the ON or OFF state depending on whether the actuating member has pivoted away from or close to the noncontact switch.
Thus, even when the human operator has turned the handling lever through a relatively great angle, the fan-shaped actuating member can remain sufficiently near the noncontact switch, so that the noncontact switch can be kept reliably in the ON or OFF state; that is, the noncontact switch can perform a stable and reliable switching function. For example, if the fan-shaped actuating member is formed to have a large size, the setting range for the ON or OFF state of the noncontact switch can be increased sufficiently, which can thus achieve a higher degree of design flexibility or freedom. Further, by providing the noncontact switch and handling lever at a short distance from each other in the switch operation mechansim, a simple and direct switching structure for the ON/OFF control of the cutter-driving electric motor can be achieved.
Further, in the present invention, the switch operation mechanism may further include a clutch mechanism, provided between the handling lever and the actuating member, for bringing the handling lever and the actuating member into or out of engagement with each other in response to the operation of the handling lever. The provision of such a clutch mechanism can effectively prevent erroneous switching operations of the operation mechanism.